To allow connection of dissimilar joints. Outer joint at the top, inner joint at the bottom. Scientists rely on the expertise and artistic skills of Wilmad-LabGlass' engineers and glass specialists to manufacture NMR and EPR consumables and laboratory glassware of the highest quality. Used daily in academia, healthcare and chemical, petroleum and other industrial applications, Wilmad offers 7000+ items as part of their standard catalog as well as custom fabrication for individual glassware, glass repair services and OEM glass parts.